1 files changed, 60 insertions, 1 deletions
diff --git a/src/test/scala/firrtlTests/options/phases/WriteOutputAnnotationsSpec.scala b/src/test/scala/firrtlTests/options/phases/WriteOutputAnnotationsSpec.scala
index e71eaedf..0a3cce67 100644
--- a/src/test/scala/firrtlTests/options/phases/WriteOutputAnnotationsSpec.scala
+++ b/src/test/scala/firrtlTests/options/phases/WriteOutputAnnotationsSpec.scala
@@ -7,7 +7,16 @@ import java.io.File
 
 import firrtl.AnnotationSeq
 import firrtl.annotations.{DeletedAnnotation, NoTargetAnnotation}
-import firrtl.options.{InputAnnotationFileAnnotation, OutputAnnotationFileAnnotation, Phase, WriteDeletedAnnotation}
+import firrtl.options.{
+  CustomFileEmission,
+  InputAnnotationFileAnnotation,
+  OutputAnnotationFileAnnotation,
+  Phase,
+  PhaseException,
+  StageOptions,
+  TargetDirAnnotation,
+  WriteDeletedAnnotation}
+import firrtl.options.Viewer.view
 import firrtl.options.phases.{GetIncludes, WriteOutputAnnotations}
 import org.scalatest.flatspec.AnyFlatSpec
 import org.scalatest.matchers.should.Matchers
@@ -100,9 +109,59 @@ class WriteOutputAnnotationsSpec extends AnyFlatSpec with Matchers with firrtl.t
     out.toSeq should be (annotations)
   }
 
+  it should "write CustomFileEmission annotations" in new Fixture {
+    val file = new File("write-CustomFileEmission-annotations.anno.json")
+    val annotations = Seq( TargetDirAnnotation(dir),
+                           OutputAnnotationFileAnnotation(file.toString),
+                           WriteOutputAnnotationsSpec.Custom("hello!") )
+    val serializedFileName = view[StageOptions](annotations).getBuildFileName("Custom", Some(".Emission"))
+    val expected = annotations.map {
+      case _: WriteOutputAnnotationsSpec.Custom => WriteOutputAnnotationsSpec.Replacement(serializedFileName)
+      case a => a
+    }
+
+    val out = phase.transform(annotations)
+
+    info("annotations are unmodified")
+    out.toSeq should be (annotations)
+
+    fileContainsAnnotations(new File(dir, file.toString), expected)
+
+    info(s"file '$serializedFileName' exists")
+    new File(serializedFileName) should (exist)
+  }
+
+  it should "error if multiple annotations try to write to the same file" in new Fixture {
+    val file = new File("write-CustomFileEmission-annotations-error.anno.json")
+    val annotations = Seq( TargetDirAnnotation(dir),
+                           OutputAnnotationFileAnnotation(file.toString),
+                           WriteOutputAnnotationsSpec.Custom("foo"),
+                           WriteOutputAnnotationsSpec.Custom("bar") )
+    intercept[PhaseException] {
+      phase.transform(annotations)
+    }.getMessage should startWith ("Multiple CustomFileEmission annotations")
+  }
+
 }
 
 private object WriteOutputAnnotationsSpec {
+
   case object FooAnnotation extends NoTargetAnnotation
+
   case class BarAnnotation(x: Int) extends NoTargetAnnotation
+
+  case class Custom(value: String) extends NoTargetAnnotation with CustomFileEmission {
+
+    override protected def baseFileName(a: AnnotationSeq): String = "Custom"
+
+    override protected def suffix: Option[String] = Some(".Emission")
+
+    override def getBytes: Iterable[Byte] = value.getBytes
+
+    override def replacements(file: File): AnnotationSeq = Seq(Replacement(file.toString))
+
+  }
+
+  case class Replacement(file: String) extends NoTargetAnnotation
+
 }